Abstract No : LBA38

Indication : Head & Neck Cancer

Intervention : Pembrolizumab + RT

Company : Merck & Co.

Technology : PD-1 inhibitor + RT

Results:

Between May 2016 and October 2017, 131 patients were randomized and treated by 27 centers: 65 patients in Cetux-RT arm and 66 patients in Pembro-RT arm. The median age was 65 years, 92% were smokers, 60% of oropharynx (46% p16+), 41% of N2c-N3 with 25%, 56% and 19% of stage III, IVa and IVb respectively. Median follow-up was 25 months in both arms. Acute toxicity was lower in Pembro-RT arm than Cetux-RT arm: 74% vs 92% patients with at least one grade ≥ 3 acute adverse events (p=0.006), mainly due to dermatitis in radiation field, mucositis and cutaneous rash. LRC at 15 months were 59% in Cetux-RT arm and 60% in Pembro-RT arm, not significantly different: OR=1.05 (95%CI: 0.43-2.59, p=0.91). 2-year PFS rate was 40% in the Cetux-RT arm vs 42% in the Pembro-RT arm. There was no significant difference between arms for PFS: HR=0.83 (95%CI 0.53-1.29, p=0.41). 2-year OS rate was 55% in the Cetux-RT arm vs 62% in the Pembro-RT arm. OS was not significantly different between arms: HR=0.83 (95%CI: 0.49-1.40, p=0.49).

Conclusion:

Compared to the SOC cetuximab-RT, the anti-PD1 pembrolizumab concomitant with RT did not improve carcinologic outcomes but appeared less toxic.